Define DNS_NAME_MAXLABELS and DNS_NAME_LABELLEN

Some qp-trie operations will need to know the maximum number of labels
in a name, so I wanted a standard macro definition with the right
value.

Replace DNS_MAX_LABELS from <dns/resolver.h with DNS_NAME_MAXLABELS in
<dns/name.h>, and add its counterpart DNS_NAME_LABELLEN.

Use these macros in `name.c` and `resolver.c`.

Fix an off-by-one error in an assertion in `dns_name_countlabels()`.

diff --git a/lib/dns/include/dns/name.h b/lib/dns/include/dns/name.h
index 359f8a08d735fc0d6e5fe530a5b9df0183efd6a4..9e3a5191b5149d8d7b6d034a25b2f56fe11fadcc 100644 (file)
--- a/lib/dns/include/dns/name.h
+++ b/lib/dns/include/dns/name.h
@@ -182,9 +182,11 @@ extern const dns_name_t *dns_wildcardname;
        }
 
 /*%
- * Standard size of a wire format name
+ * Standard sizes of a wire format name
  */
-#define DNS_NAME_MAXWIRE 255
+#define DNS_NAME_MAXWIRE   255
+#define DNS_NAME_MAXLABELS 127
+#define DNS_NAME_LABELLEN  63
 
 /*
  * Text output filter procedure.

diff --git a/lib/dns/include/dns/resolver.h b/lib/dns/include/dns/resolver.h
index df74cd5e2aecf936a5f3a45956d6abd32840934e..34a3f2e6ebdbd229faf5c8916902cdffcdc9511b 100644 (file)
--- a/lib/dns/include/dns/resolver.h
+++ b/lib/dns/include/dns/resolver.h
@@ -177,7 +177,6 @@ typedef enum { dns_quotatype_zone = 0, dns_quotatype_server } dns_quotatype_t;
 
 #define DNS_QMIN_MAXLABELS        7
 #define DNS_QMIN_MAX_NO_DELEGATION 3
-#define DNS_MAX_LABELS            127
 
 isc_result_t
 dns_resolver_create(dns_view_t *view, isc_loopmgr_t *loopmgr,

diff --git a/lib/dns/name.c b/lib/dns/name.c
index 3a5491176ad5a81d139ce0f29e3d719f0ad5f905..039b9b17f57e44fd76342c40141f81317eebdc87 100644 (file)
--- a/lib/dns/name.c
+++ b/lib/dns/name.c
@@ -149,7 +149,9 @@ dns_name_isvalid(const dns_name_t *name) {
                return (false);
        }
 
-       if (name->length > 255U || name->labels > 127U) {
+       if (name->length > DNS_NAME_MAXWIRE ||
+           name->labels > DNS_NAME_MAXLABELS)
+       {
                return (false);
        }
 
@@ -161,7 +163,7 @@ dns_name_isvalid(const dns_name_t *name) {
 
        while (offset != length) {
                count = *ndata;
-               if (count > 63U) {
+               if (count > DNS_NAME_LABELLEN) {
                        return (false);
                }
                if (offsets != NULL && offsets[nlabels] != offset) {
@@ -253,7 +255,7 @@ dns_name_ismailbox(const dns_name_t *name) {
 
        ndata = name->ndata;
        n = *ndata++;
-       INSIST(n <= 63);
+       INSIST(n <= DNS_NAME_LABELLEN);
        while (n--) {
                ch = *ndata++;
                if (!domainchar(ch)) {
@@ -270,7 +272,7 @@ dns_name_ismailbox(const dns_name_t *name) {
         */
        while (ndata < (name->ndata + name->length)) {
                n = *ndata++;
-               INSIST(n <= 63);
+               INSIST(n <= DNS_NAME_LABELLEN);
                first = true;
                while (n--) {
                        ch = *ndata++;
@@ -319,7 +321,7 @@ dns_name_ishostname(const dns_name_t *name, bool wildcard) {
         */
        while (ndata < (name->ndata + name->length)) {
                n = *ndata++;
-               INSIST(n <= 63);
+               INSIST(n <= DNS_NAME_LABELLEN);
                first = true;
                while (n--) {
                        ch = *ndata++;
@@ -377,7 +379,7 @@ dns_name_internalwildcard(const dns_name_t *name) {
         */
        ndata = name->ndata;
        count = *ndata++;
-       INSIST(count <= 63);
+       INSIST(count <= DNS_NAME_LABELLEN);
        ndata += count;
        label = 1;
        /*
@@ -385,7 +387,7 @@ dns_name_internalwildcard(const dns_name_t *name) {
         */
        while (label + 1 < name->labels) {
                count = *ndata++;
-               INSIST(count <= 63);
+               INSIST(count <= DNS_NAME_LABELLEN);
                if (count == 1 && *ndata == '*') {
                        return (true);
                }
@@ -687,7 +689,7 @@ dns_name_countlabels(const dns_name_t *name) {
 
        REQUIRE(VALID_NAME(name));
 
-       ENSURE(name->labels <= 128);
+       ENSURE(name->labels <= DNS_NAME_MAXLABELS);
 
        return (name->labels);
 }
@@ -920,8 +922,8 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
        tused = 0;
        ndata = isc_buffer_used(target);
        nrem = isc_buffer_availablelength(target);
-       if (nrem > 255) {
-               nrem = 255;
+       if (nrem > DNS_NAME_MAXWIRE) {
+               nrem = DNS_NAME_MAXWIRE;
        }
        nused = 0;
        labels = 0;
@@ -977,7 +979,7 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
                                }
                                *label = count;
                                labels++;
-                               INSIST(labels <= 127);
+                               INSIST(labels <= DNS_NAME_MAXLABELS);
                                offsets[labels] = nused;
                                if (tlen == 0) {
                                        labels++;
@@ -990,7 +992,7 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
                        } else if (c == '\\') {
                                state = ft_escape;
                        } else {
-                               if (count >= 63) {
+                               if (count >= DNS_NAME_LABELLEN) {
                                        return (DNS_R_LABELTOOLONG);
                                }
                                count++;
@@ -1015,7 +1017,7 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
                        FALLTHROUGH;
                case ft_escape:
                        if (!isdigit((unsigned char)c)) {
-                               if (count >= 63) {
+                               if (count >= DNS_NAME_LABELLEN) {
                                        return (DNS_R_LABELTOOLONG);
                                }
                                count++;
@@ -1042,7 +1044,7 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
                                if (value > 255) {
                                        return (DNS_R_BADESCAPE);
                                }
-                               if (count >= 63) {
+                               if (count >= DNS_NAME_LABELLEN) {
                                        return (DNS_R_LABELTOOLONG);
                                }
                                count++;
@@ -1074,7 +1076,7 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
                        INSIST(label != NULL);
                        *label = count;
                        labels++;
-                       INSIST(labels <= 127);
+                       INSIST(labels <= DNS_NAME_MAXLABELS);
                        offsets[labels] = nused;
                }
                if (origin != NULL) {
@@ -1087,7 +1089,7 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
                        POST(nrem);
                        while (n1 > 0) {
                                n2 = *label++;
-                               INSIST(n2 <= 63); /* no bitstring support */
+                               INSIST(n2 <= DNS_NAME_LABELLEN);
                                *ndata++ = n2;
                                n1 -= n2 + 1;
                                nused += n2 + 1;
@@ -1101,7 +1103,7 @@ dns_name_fromtext(dns_name_t *name, isc_buffer_t *source,
                                }
                                labels++;
                                if (n1 > 0) {
-                                       INSIST(labels <= 127);
+                                       INSIST(labels <= DNS_NAME_MAXLABELS);
                                        offsets[labels] = nused;
                                }
                        }
@@ -1220,7 +1222,7 @@ dns_name_totext2(const dns_name_t *name, unsigned int options,
                        saw_root = true;
                        break;
                }
-               if (count < 64) {
+               if (count <= DNS_NAME_LABELLEN) {
                        INSIST(nlen >= count);
                        while (count > 0) {
                                c = *ndata;
@@ -1365,7 +1367,7 @@ dns_name_tofilenametext(const dns_name_t *name, bool omit_final_dot,
                if (count == 0) {
                        break;
                }
-               if (count < 64) {
+               if (count <= DNS_NAME_LABELLEN) {
                        INSIST(nlen >= count);
                        while (count > 0) {
                                c = *ndata;
@@ -1495,10 +1497,10 @@ set_offsets(const dns_name_t *name, unsigned char *offsets,
        nlabels = 0;
        absolute = false;
        while (offset != length) {
-               INSIST(nlabels < 128);
+               INSIST(nlabels <= DNS_NAME_MAXLABELS);
                offsets[nlabels++] = offset;
                count = *ndata;
-               INSIST(count <= 63);
+               INSIST(count <= DNS_NAME_LABELLEN);
                offset += count + 1;
                ndata += count + 1;
                INSIST(offset <= length);
@@ -1622,7 +1624,7 @@ dns_name_fromwire(dns_name_t *const name, isc_buffer_t *const source,
         */
        while (cursor < source_max) {
                const uint8_t label_len = *cursor++;
-               if (label_len < 64) {
+               if (label_len <= DNS_NAME_LABELLEN) {
                        /*
                         * Normal label: record its offset, and check bounds on
                         * the name length, which also ensures we don't overrun

diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index b18563a92ab7c2c415c28d695c9aff1aabfcc181..89d697860b60c982df5356f57083e044033e218a 100644 (file)
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -51,6 +51,7 @@
 #include <dns/keytable.h>
 #include <dns/log.h>
 #include <dns/message.h>
+#include <dns/name.h>
 #include <dns/ncache.h>
 #include <dns/nsec.h>
 #include <dns/nsec3.h>
@@ -4361,7 +4362,7 @@ resume_qmin(void *arg) {
        case ISC_R_FAILURE:
                if ((fctx->options & DNS_FETCHOPT_QMIN_STRICT) == 0) {
                        /* Disable minimization in relaxed mode */
-                       fctx->qmin_labels = DNS_MAX_LABELS + 1;
+                       fctx->qmin_labels = DNS_NAME_MAXLABELS + 1;
                        /*
                         * We store the result. If we succeed in the end
                         * we'll issue a warning that the server is
@@ -10414,7 +10415,7 @@ fctx_minimize_qname(fetchctx_t *fctx) {
                        fctx->qmin_labels = nlabels;
                }
        } else if (fctx->qmin_labels > DNS_QMIN_MAXLABELS) {
-               fctx->qmin_labels = DNS_MAX_LABELS + 1;
+               fctx->qmin_labels = DNS_NAME_MAXLABELS + 1;
        }
 
        if (fctx->qmin_labels < nlabels) {